HVAC controller with user-friendly installation features facilitating both do-it-yourself and professional installation scenarios

ABSTRACT

A thermostat may include a processing system, a plurality of HVAC connectors configured to receive a corresponding plurality of HVAC control wires, and a connection sensing circuit coupled to the plurality of HVAC connectors and configured to provide an indication to the processing system of whether a wire is inserted for each of the plurality of HVAC connectors. The processing system may be configured to receive an indication from the connection sensing circuit when an HVAC connector in the plurality of HVAC connectors has a wire inserted therein, the HVAC connector being associated with a plurality of possible HVAC functions. The processing system may also be configured to display the plurality of possible HVAC functions on a user interface, to receive input selecting one of the possible HVAC functions for the HVAC connector, and to operate the selected HVAC function through the HVAC connector.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/036,701, filed Sep. 25, 2013, which is a continuation of U.S. patentapplication Ser. No. 13/632,148, filed Sep. 30, 2012, now U.S. Pat. No.8,544,285, which is a continuation-in-part of U.S. patent applicationSer. No. 13/269,501 filed Oct. 7, 2011, now U.S. Pat. No. 8,918,219.U.S. patent application Ser. No. 13/632,148 also claims the benefit ofU.S. Provisional Application No. 61/627,996, filed Oct. 21, 2011. Eachof the above-referenced patent applications is incorporated by referenceherein.

TECHNICAL FIELD

This patent specification relates to systems and methods for themonitoring and control of energy-consuming systems or otherresource-consuming systems. More particularly, this patent specificationrelates to control units that govern the operation of energy-consumingsystems, household devices, or other resource-consuming systems,including methods for activating electronic displays for thermostatsthat govern the operation of heating, ventilation, and air conditioning(HVAC) systems.

BACKGROUND OF THE INVENTION

While substantial effort and attention continues toward the developmentof newer and more sustainable energy supplies, the conservation ofenergy by increased energy efficiency remains crucial to the world'senergy future. According to an October 2010 report from the U.S.Department of Energy, heating and cooling account for 56% of the energyuse in a typical U.S. home, making it the largest energy expense formost homes. Along with improvements in the physical plant associatedwith home heating and cooling (e.g., improved insulation, higherefficiency furnaces), substantial increases in energy efficiency can beachieved by better control and regulation of home heating and coolingequipment. By activating heating, ventilation, and air conditioning(HVAC) equipment for judiciously selected time intervals and carefullychosen operating levels, substantial energy can be saved while at thesame time keeping the living space suitably comfortable for itsoccupants.

Historically, however, most known HVAC thermostatic control systems havetended to fall into one of two opposing categories, neither of which isbelieved be optimal in most practical home environments. In a firstcategory are many simple, non-programmable home thermostats, eachtypically consisting of a single mechanical or electrical dial forsetting a desired temperature and a single HEAT-FAN-OFF-AC switch. Whilebeing easy to use for even the most unsophisticated occupant, anyenergy-saving control activity, such as adjusting the nighttimetemperature or turning off all heating/cooling just before departing thehome, must be performed manually by the user. As such, substantialenergy-saving opportunities are often missed for all but the mostvigilant users. Moreover, more advanced energy-saving settings are notprovided, such as the ability to specify a custom temperature swing,i.e., the difference between the desired set temperature and actualcurrent temperature (such as 1 to 3 degrees) required to trigger turn-onof the heating/cooling unit.

In a second category, on the other hand, are many programmablethermostats, which have become more prevalent in recent years in view ofEnergy Star (US) and TCO (Europe) standards, and which have progressedconsiderably in the number of different settings for an HVAC system thatcan be individually manipulated. Unfortunately, however, users are oftenintimidated by a dizzying array of switches and controls laid out invarious configurations on the face of the thermostat or behind a paneldoor on the thermostat, and seldom adjust the manufacturer defaults tooptimize their own energy usage. Thus, even though the installedprogrammable thermostats in a large number of homes are technologicallycapable of operating the HVAC equipment with energy-saving profiles, itis often the case that only the one-size-fits-all manufacturer defaultprofiles are ever implemented in a large number of homes. Indeed, in anunfortunately large number of cases, a home user may permanently operatethe unit in a “temporary” or “hold” mode, manually manipulating thedisplayed set temperature as if the unit were a simple, non-programmablethermostat.

In a more general sense, important issues arise at the interface between(i) energy-saving technologies that might be achievable using knownsensing and processing methods, and (ii) the actual widespread useradoption of devices that implement such energy-saving technologies andthe integration of those devices into their daily routines andenvironment. It has been found especially important that the “firstcontact” between a user and an energy-saving device constitute aparticularly easy, enjoyable, and pleasant experience, or else the usercan quickly “turn off” or “tune out” to the device and its energy-savingadvantages.

Although the scope of the present teachings hereinbelow is notnecessarily limited to thermostats but rather can extend to a variety ofdifferent smart-home devices, the installation of an intelligent,energy-saving, network-connected thermostat presents particular issuesthat are well addressed by one or more of the embodiments herein. Onethe one hand, it is desirable to provide an intelligent, energy-saving,network-connected a thermostat that accommodates easy do-it-yourselfinstallation for ordinary users who desire to perform their owninstallation. On the other hand, because HVAC equipment configurationsin some homes can get rather complex, and because the consequences ofimproper installation can sometimes be severe, it is sometimes importantthat professionals get involved in the installation process.

It would be desirable to provide an intelligent, energy-saving,network-connected thermostat that can provide both do-it-yourselfsimplicity in scenarios where that is proper and safe, and yet that alsohas the ability to accommodate more complex HVAC systems and identifythe potential need for professional assistance, all while beinguser-friendly and providing a pleasing first contact with the user aswell as any professionals who may ultimately get involved. Other issuesarise as would be apparent to a person skilled in the art in view of thepresent disclosure.

BRIEF SUMMARY OF THE INVENTION

According to one embodiment, a thermostat may be presented. Thethermostat may include a processing system. The processing system may beconfigured to be in operative communication with a heating, ventilation,and air conditioning (HVAC) system to control the HVAC system. Thethermostat may also include a plurality of HVAC connectors configured toreceive a corresponding plurality of HVAC control wires corresponding tothe HVAC system. The thermostat may additionally include, a connectionsensing module coupled to the plurality of HVAC connectors andconfigured to determine identities of a first subset of the plurality ofHVAC connectors into which corresponding HVAC wires have been inserted,wherein the processing system is further configured to process theidentities of the first subset of HVAC connectors to determine aconfiguration of the HVAC system to be controlled. In one embodiment,the processing may include identifying, based on said identities of thefirst subset of HVAC connectors, whether (i) only a single possible HVACsystem configuration is indicated thereby, or (ii) multiple possibleHVAC system configurations are indicated thereby. The processing mayfurther include operating, if the single possible HVAC systemconfiguration is indicated, the HVAC system according to said singlepossible HVAC system configuration. The processing may additionallyinclude resolving, if the multiple possible HVAC system configurationsare indicated, a particular one of the multiple possible HVAC systemconfigurations that is applicable, and operating the HVAC systemaccording to the resolved particular HVAC system configuration.

In another embodiment, a method of determining HVAC system configurationfor an HVAC system for control by a thermostat may be presented. Themethod may include determining identities of a first subset of aplurality of HVAC connectors into which corresponding HVAC wires havebeen inserted, wherein the plurality of HVAC connectors are configuredto receive a corresponding plurality of HVAC control wires correspondingto the HVAC system. The method may also include identifying, based onthe identities of the first subset of HVAC connectors, whether (i) onlya single possible HVAC system configuration is indicated thereby, or(ii) multiple possible HVAC system configurations are indicated thereby.The method may additionally include operating, if the single possibleHVAC system configuration is indicated, the HVAC system according to thesingle possible HVAC system configuration. The method may furtherinclude resolving, if the multiple possible HVAC system configurationsare indicated, a particular one of the multiple possible HVAC systemconfigurations that is applicable, and operating said HVAC systemaccording to the resolved particular HVAC system configuration. In oneembodiment, the resolving is performed at least in part by a processingsystem, the processing system being configured to be in operativecommunication with the HVAC system to control the HVAC system.

In yet another embodiment, another thermostat may be presented. Thethermostat may include a processing system, a power stealing circuitcoupled to the processing system and configured to provide power to thethermostat using a rechargeable battery, a plurality of HVAC connectorsconfigured to receive a corresponding plurality of HVAC control wires,and a connection sensing module coupled to the plurality of HVACconnectors and configured to provide an indication to the processingsystem whether a wire is mechanically inserted for each of the pluralityof HVAC connectors. The processing system may be configured to determinean HVAC system configuration by identifying a subset of the plurality ofHVAC connectors into which a wire has been mechanically inserted,identifying an ambiguity resulting from the subset, resolving theambiguity resulting from the subset to determine the HVAC systemconfiguration; and operating the HVAC system in accordance with the HVACsystem configuration.

A further understanding of the nature and advantages of the presentinvention may be realized by reference to the remaining portions of thespecification and the drawings. Also note that other embodiments may bedescribed in the following disclosure and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a thermostat, according to oneembodiment.

FIG. 2 illustrates an exploded perspective view of a thermostat having ahead unit and the backplate, according to one embodiment.

FIG. 3A illustrates an exploded perspective view of a head unit withrespect to its primary components, according to one embodiment.

FIG. 3B illustrates an exploded perspective view of a backplate withrespect to its primary components, according to one embodiment.

FIG. 4A illustrates a simplified functional block diagram for a headunit, according to one embodiment.

FIG. 4B illustrates a simplified functional block diagram for abackplate, according to one embodiment.

FIG. 5 illustrates a simplified circuit diagram of a system for managingthe power consumed by a thermostat, according to one embodiment.

FIG. 6 illustrates steps for automated system matching that can becarried out by a thermostat, according to one embodiment.

FIGS. 7A-7B are diagrams showing a thermostat backplate having aplurality of wiring terminals, according to some embodiments.

FIG. 8 illustrates a flowchart of a method for determining an HVACconfiguration using wire connectors, according to one embodiment.

FIG. 9 illustrates a flowchart of a method of determining whether anHVAC system uses a heat pump, according to one embodiment.

FIG. 10 illustrates a flowchart of a method for determining an HVACsystem configuration for a conventional HVAC system, according to oneembodiment.

FIG. 11 illustrates a flowchart of a method for determining an HVACsystem configuration for one-stage or two-stage conventional heating,according to one embodiment.

FIG. 12 illustrates a flowchart of a method for determining an HVACsystem configuration for a heat pump system with a W3 wire connection,according to one embodiment.

FIG. 13 illustrates a flowchart of a method for determining an HVACsystem configuration for a heat pump system without the W3 wireconnection, according to one embodiment.

FIG. 14A illustrates a user interface of a thermostat for providing anoutput describing a wiring error, according to one embodiment.

FIG. 14B illustrates a user interface of a thermostat providing agraphical output of mechanical wiring connections that have beendetected, according to one embodiment.

FIG. 15A illustrates a user interface of a thermostat providing agraphical output of multiple wiring connections, according to oneembodiment.

FIG. 15B illustrates a corresponding user interface of a thermostatproviding a graphical wiring diagram, according to one embodiment.

FIG. 16A illustrates a user interface of a thermostat providing agraphical description of a current wiring configuration, according toone embodiment.

FIG. 16B illustrates a thermostat user interface providing additionalinformation for a particular connector, according to one embodiment.

FIG. 17A illustrates a thermostat with a user interface displaying aconnection to a wildcard connector, according to one embodiment.

FIG. 17B illustrates a thermostat with a user interface displaying aconfiguration screen for the wildcard connector, according to oneembodiment.

FIG. 18A illustrates a settings screen for accessing a professionalsetup interface.

FIG. 18B illustrates a warning that may be displayed for professionalsetup, according to one embodiment.

DETAILED DESCRIPTION OF THE INVENTION

The subject matter of this patent specification relates to the subjectmatter of the following commonly assigned applications, each of which isincorporated by reference herein: U.S. Ser. No. 13/034,666 filed Feb.24, 2011; U.S. Ser. No. 13/038,191 filed Mar. 1, 2011; U.S. Ser. No.13/467,029 filed May 8, 2012; and U.S. Ser. No. 13/624,878 filed Sep.21, 2012. The above-referenced patent applications are collectivelyreferenced herein as “the commonly-assigned incorporated applications.”

In the following detailed description, for purposes of explanation,numerous specific details are set forth to provide a thoroughunderstanding of the various embodiments of the present invention. Thoseof ordinary skill in the art will realize that these various embodimentsof the present invention are illustrative only and are not intended tobe limiting in any way. Other embodiments of the present invention willreadily suggest themselves to such skilled persons having the benefit ofthis disclosure.

In addition, for clarity purposes, not all of the routine features ofthe embodiments described herein are shown or described. One of ordinaryskill in the art would readily appreciate that in the development of anysuch actual embodiment, numerous embodiment-specific decisions may berequired to achieve specific design objectives. These design objectiveswill vary from one embodiment to another and from one developer toanother. Moreover, it will be appreciated that such a development effortmight be complex and time-consuming but would nevertheless be a routineengineering undertaking for those of ordinary skill in the art havingthe benefit of this disclosure.

It is to be appreciated that while one or more embodiments are describedfurther herein in the context of typical HVAC system used in aresidential home, such as single-family residential home, the scope ofthe present teachings is not so limited. More generally, thermostatsaccording to one or more of the preferred embodiments are applicable fora wide variety of enclosures having one or more HVAC systems including,without limitation, duplexes, townhomes, multi-unit apartment buildings,hotels, retail stores, office buildings, and industrial buildings.Further, it is to be appreciated that while the terms user, customer,installer, homeowner, occupant, guest, tenant, landlord, repair person,and/or the like may be used to refer to the person or persons who areinteracting with the thermostat or other device or user interface in thecontext of one or more scenarios described herein, these references areby no means to be considered as limiting the scope of the presentteachings with respect to the person or persons who are performing suchactions.

Exemplary Thermostat Embodiments

Provided according to one or more embodiments are systems, methods, andcomputer program products for controlling one or more HVAC systems basedon one or more versatile sensing and control units (VSCU units), eachVSCU unit being configured and adapted to provide sophisticated,customized, energy-saving HVAC control functionality while at the sametime being visually appealing, non-intimidating, and easy to use. Theterm “thermostat” is used herein below to represent a particular type ofVSCU unit (Versatile Sensing and Control) that is particularlyapplicable for HVAC control in an enclosure. Although “thermostat” and“VSCU unit” may be seen as generally interchangeable for the contexts ofHVAC control of an enclosure, it is within the scope of the presentteachings for each of the embodiments herein to be applied to VSCU unitshaving control functionality over measurable characteristics other thantemperature (e.g., pressure, flow rate, height, position, velocity,acceleration, capacity, power, loudness, brightness) for any of avariety of different control systems involving the governance of one ormore measurable characteristics of one or more physical systems, and/orthe governance of other energy or resource consuming systems such aswater usage systems, air usage systems, systems involving the usage ofother natural resources, and systems involving the usage of variousother forms of energy.

FIGS. 1-5 and the descriptions in relation thereto provide exemplaryembodiments of thermostat hardware and/or software that can be used toimplement the specific embodiments of the appended claims. Thisthermostat hardware and/or software is not meant to be limiting, and ispresented to provide an enabling disclosure. FIG. 1 illustrates aperspective view of a thermostat 100, according to one embodiment. Inthis specific embodiment, the thermostat 100 can be controlled by atleast two types of user input, the first being a rotation of the outerring 112, and the second being an inward push on an outer cap 108 untilan audible and/or tactile “click” occurs. As used herein, these twotypes of user inputs, may be referred to as “manipulating” thethermostat. In other embodiments, manipulating the thermostat may alsoinclude pressing keys on a keypad, voice recognition commands, and/orany other type of input that can be used to change or adjust settings onthe thermostat 100.

For this embodiment, the outer cap 108 can comprise an assembly thatincludes the outer ring 112, a cover 114, an electronic display 116, anda metallic portion 124. Each of these elements, or the combination ofthese elements, may be referred to as a “housing” for the thermostat100. Simultaneously, each of these elements, or the combination of theseelements, may also form a user interface. The user interface mayspecifically include the electronic display 116. In FIG. 1, the userinterface 116 may be said to operate in an active display mode. Theactive display mode may include providing a backlight for the electronicdisplay 116. In other embodiments, the active display mode may increasethe intensity and/or light output of the electronic display 116 suchthat a user can easily see displayed settings of the thermostat 100,such as a current temperature, a setpoint temperature, an HVAC function,and/or the like. The active display mode may be contrasted with aninactive display mode (not shown). The inactive display mode can disablea backlight, reduce the amount of information displayed, lessen theintensity of the display, and/or altogether turn off the electronicdisplay 116, depending on the embodiment.

Depending on the settings of the thermostat 100, the active display modeand the inactive display mode of the electronic display 116 may also orinstead be characterized by the relative power usage of each mode. Inone embodiment, the active display mode may generally requiresubstantially more electrical power than the inactive display mode. Insome embodiments, different operating modes of the electronic display116 may instead be characterized completely by their power usage. Inthese embodiments, the different operating modes of the electronicdisplay 116 may be referred to as a first mode and a second mode, wherethe user interface requires more power when operating in the first modethan when operating in the second mode.

According to some embodiments the electronic display 116 may comprise adot-matrix layout (individually addressable) such that arbitrary shapescan be generated, rather than being a segmented layout. According tosome embodiments, a combination of dot-matrix layout and segmentedlayout is employed. According to some embodiments, electronic display116 may be a backlit color liquid crystal display (LCD). An example ofinformation displayed on the electronic display 116 is illustrated inFIG. 1, and includes central numerals 120 that are representative of acurrent setpoint temperature. According to some embodiments, metallicportion 124 can have a number of slot-like openings so as to facilitatethe use of a sensors 130, such as a passive infrared motion sensor(PIR), mounted beneath the slot-like openings.

According to some embodiments, the thermostat 100 can include additionalcomponents, such as a processing system 160, display driver 164, and awireless communications system 166. The processing system 160 canadapted or configured to cause the display driver 164 to cause theelectronic display 116 to display information to the user. Theprocessing system 160 can also be configured to receive user input viathe rotatable ring 112. These additional components, including theprocessing system 160, can be enclosed within the housing, as displayedin FIG. 1. These additional components are described in further detailherein below.

The processing system 160, according to some embodiments, is capable ofcarrying out the governance of the thermostat's operation. For example,processing system 160 can be further programmed and/or configured tomaintain and update a thermodynamic model for the enclosure in which theHVAC system is installed. According to some embodiments, the wirelesscommunications system 166 can be used to communicate with devices suchas personal computers, remote servers, handheld devices, smart phones,and/or other thermostats or HVAC system components. These communicationscan be peer-to-peer communications, communications through one or moreservers located on a private network, or and/or communications through acloud-based service.

Motion sensing as well as other techniques can be use used in thedetection and/or prediction of occupancy, as is described further in thecommonly assigned U.S. Ser. No. 12/881,430, supra. According to someembodiments, occupancy information can be a used in generating aneffective and efficient scheduled program. For example, an activeproximity sensor 170A can be provided to detect an approaching user byinfrared light reflection, and an ambient light sensor 170B can beprovided to sense visible light. The proximity sensor 170A can be usedin conjunction with a plurality of other sensors to detect proximity inthe range of about one meter so that the thermostat 100 can initiate“waking up” when the user is approaching the thermostat and prior to theuser touching the thermostat. Such use of proximity sensing is usefulfor enhancing the user experience by being “ready” for interaction assoon as, or very soon after the user is ready to interact with thethermostat. Further, the wake-up-on-proximity functionality also allowsfor energy savings within the thermostat by “sleeping” when no userinteraction is taking place or about to take place. The various types ofsensors that may be used, as well as the operation of the “wake up”function are described in much greater detail throughout the remainderof this disclosure.

In some embodiments, the thermostat can be physically and/orfunctionally divided into at least two different units. Throughout thisdisclosure, these two units can be referred to as a head unit and abackplate. FIG. 2 illustrates an exploded perspective view 200 of athermostat 208 having a head unit 210 and a backplate 212, according toone embodiment. Physically, this arrangement may be advantageous duringan installation process. In this embodiment, the backplate 212 can firstbe attached to a wall, and the HVAC wires can be attached to a pluralityof HVAC connectors on the backplate 212. Next, the head unit 210 can beconnected to the backplate 212 in order to complete the installation ofthe thermostat 208.

FIG. 3A illustrates an exploded perspective view 300 a of a head unit330 with respect to its primary components, according to one embodiment.Here, the head unit 330 may include an electronic display 360. Accordingto this embodiment, the electronic display 360 may comprise an LCDmodule. Furthermore, the head unit 330 may include a mounting assembly350 used to secure the primary components in a completely assembled headunit 330. The head unit 330 may further include a circuit board 340 thatcan be used to integrate various electronic components described furtherbelow. In this particular embodiment, the circuit board 340 of the headunit 330 can include a manipulation sensor 342 to detect usermanipulations of the thermostat. In embodiments using a rotatable ring,the manipulation sensor 342 may comprise an optical finger navigationmodule as illustrated in FIG. 3A. A rechargeable battery 344 may also beincluded in the assembly of the head unit 330. In one preferredembodiment, rechargeable battery 344 can be a Lithium-Ion battery, whichmay have a nominal voltage of 3.7 volts and a nominal capacity of 560mAh.

FIG. 3B illustrates an exploded perspective view 300 b of a backplate332 with respect to its primary components, according to one embodiment.The backplate 332 may include a frame 310 that can be used to mount,protect, or house a backplate circuit board 320. The backplate circuitboard 320 may be used to mount electronic components, including one ormore processing functions, and/or one or more HVAC wire connectors 322.The one or more HVAC wire connectors 322 may include integrated wireinsertion sensing circuitry configured to determine whether or not awire is mechanically and/or electrically connected to each of the one ormore HVAC wire connectors 322. In this particular embodiment, tworelatively large capacitors 324 are a part of power stealing circuitrythat can be mounted to the backplate circuit board 320. The powerstealing circuitry is discussed further herein below.

In addition to physical divisions within the thermostat that simplifyinstallation process, the thermostat may also be divided functionallybetween the head unit and the backplate. FIG. 4A illustrates asimplified functional block diagram 400 a for a head unit, according toone embodiment. The functions embodied by block diagram 400 a arelargely self-explanatory, and may be implemented using one or moreprocessing functions. As used herein, the term “processing function” mayrefer to any combination of hardware and/or software. For example, aprocessing function may include a microprocessor, a microcontroller,distributed processors, a lookup table, digital logic,logical/arithmetic functions implemented in analog circuitry, and/or thelike. A processing function may also be referred to as a processingsystem, a processing circuit, or simply a circuit.

In this embodiment, a processing function on the head unit may beimplemented by an ARM processor. The head unit processing function mayinterface with the electronic display 402, an audio system 404, and amanipulation sensor 406 as a part of a user interface 408. The head unitprocessing function may also facilitate wireless communications 410 byinterfacing with various wireless modules, such as a Wi-Fi module 412and/or a ZigBee module 414. Furthermore, the head unit processingfunction may be configured to control the core thermostat operations416, such as operating the HVAC system. The head unit processingfunction may further be configured to determine or sense occupancy 418of a physical location, and to determine building characteristics 420that can be used to determine time-to-temperature characteristics. Usingthe occupancy sensing 418, the processing function on the head unit mayalso be configured to learn and manage operational schedules 422, suchas diurnal heat and cooling schedules. A power management module 462 maybe used to interface with a corresponding power management module on theback plate, the rechargeable battery, and a power control circuit 464 onthe back plate.

Additionally, the head unit processing function may include and/or becommunicatively coupled to one or more memories. The one or morememories may include one or more sets of instructions that cause theprocessing function to operate as described above. The one or morememories may also include a sensor history and global state objects 424.The one or more memories may be integrated with the processing function,such as a flash memory or RAM memory available on many commercialmicroprocessors. The head unit processing function may also beconfigured to interface with a cloud management system 426, and may alsooperate to conserve energy wherever appropriate 428. An interface 432 toa backplate processing function 430 may also be included, and may beimplemented using a hardware connector.

FIG. 4B illustrates a simplified functional block diagram for abackplate, according to one embodiment. Using an interface 436 that ismatched to the interface 432 shown in FIG. 4A, the backplate processingfunction can communicate with the head unit processing function 438. Thebackplate processing function can include wire insertion sensing 440that is coupled to external circuitry 442 configured to provide signalsbased on different wire connection states. The backplate processingfunction may be configured to manage the HVAC switch actuation 444 bydriving power FET circuitry 446 to control the HVAC system.

The backplate processing function may also include a sensor pollinginterface 448 to interface with a plurality of sensors. In thisparticular embodiment, the plurality of sensors may include atemperature sensor, a humidity sensor, a PIR sensor, a proximity sensor,an ambient light sensor, and or other sensors not specifically listed.This list is not meant to be exhaustive. Other types of sensors may beused depending on the particular embodiment and application, such assound sensors, flame sensors, smoke detectors, and/or the like. Thesensor polling interface 448 may be communicatively coupled to a sensorreading memory 450. The sensor reading memory 450 can store sensorreadings and may be located internally or externally to amicrocontroller or microprocessor.

Finally, the backplate processing function can include a powermanagement unit 460 that is used to control various digital and/oranalog components integrated with the backplate and used to manage thepower system of the thermostat. Although one having skill in the artwill recognize many different implementations of a power managementsystem, the power management system of this particular embodiment caninclude a bootstrap regulator 462, a power stealing circuit 464, a buckconverter 466, and/or a battery controller 468.

FIG. 5 illustrates a simplified circuit diagram 500 of a system formanaging the power consumed by a thermostat, according to oneembodiment. The powering circuitry 510 comprises a full-wave bridgerectifier 520, a storage and waveform-smoothing bridge output capacitor522 (which can be, for example, on the order of 30 microfarads), a buckregulator circuit 524, a power-and-battery (PAB) regulation circuit 528,and a rechargeable lithium-ion battery 530. In conjunction with othercontrol circuitry including backplate power management circuitry 527,head unit power management circuitry 529, and the microcontroller 508,the powering circuitry 510 can be configured and adapted to have thecharacteristics and functionality described herein below. Description offurther details of the powering circuitry 510 and associated componentscan be found elsewhere in the instant disclosure and/or in the commonlyassigned U.S. Ser. No. 13/034,678, supra, and U.S. Ser. No. 13/267,871,supra.

By virtue of the configuration illustrated in FIG. 5, when there is a“C” wire presented upon installation, the powering circuitry 510operates as a relatively high-powered, rechargeable-battery-assistedAC-to-DC converting power supply. When there is not a “C” wirepresented, the powering circuitry 510 operates as a power-stealing,rechargeable-battery-assisted AC-to-DC converting power supply. Thepowering circuitry 510 generally serves to provide the voltage Vcc MAINthat is used by the various electrical components of the thermostat,which in one embodiment can be about 4.0 volts. For the case in whichthe “C” wire is present, there is no need to worry about accidentallytripping (as there is in inactive power stealing) or untripping (foractive power stealing) an HVAC call relay, and therefore relativelylarge amounts of power can be assumed to be available. Generally, thepower supplied by the “C” wire will be greater than the instantaneouspower required at any time by the remaining circuits in the thermostat.

However, a “C” wire will typically only be present in about 20% ofhomes. Therefore, the powering circuitry 510 may also be configured to“steal” power from one of the other HVAC wires in the absence of a “C”wire. As used herein, “inactive power stealing” refers to the powerstealing that is performed during periods in which there is no activecall in place based on the lead from which power is being stolen. Thus,for cases where it is the “Y” lead from which power is stolen, “inactivepower stealing” refers to the power stealing that is performed whenthere is no active cooling call in place. As used herein, “active powerstealing” refers to the power stealing that is performed during periodsin which there is an active call in place based on the lead from whichpower is being stolen. Thus, for cases where it is the “Y” lead fromwhich power is stolen, “active power stealing” refers to the powerstealing that is performed when there is an active cooling call inplace. During inactive or active power stealing, power can be stolenfrom a selected one of the available call relay wires. While a completedescription of the power stealing circuitry 510 can be found in thecommonly assigned applications that have been previously incorporatedherein by reference, the following brief explanation is sufficient forpurposes of this disclosure.

Some components in the thermostat, such as the head unit processingfunction, the user interface, and/or the electronic display may consumemore instantaneous power than can be provided by power stealing alone.When these more power-hungry components are actively operating, thepower supplied by power stealing can be supplemented with therechargeable battery 530. In other words, when the thermostat is engagedin operations, such as when the electronic display is in an activedisplay mode, power may be supplied by both power stealing and therechargeable battery 530. In order to preserve the power stored in therechargeable battery 530, and to give the rechargeable battery 530 anopportunity to recharge, some embodiments optimize the amount of timethat the head unit processing function and the electronic display areoperating in an active mode. In other words, it may be advantageous insome embodiments to keep the head unit processing function in a sleepmode or low power mode and to keep the electronic display in an inactivedisplay mode as long as possible without affecting the user experience.

When the head unit processing function and the electronic display are inan inactive or sleep mode, the power consumed by the thermostat isgenerally less than the power provided by power stealing. Therefore, thepower that is not consumed by the thermostat can be used to recharge therechargeable battery 530. In this embodiment, the backplate processingfunction 508 (MSP430) can be configured to monitor the environmentalsensors in a low-power mode, and then wake the head unit processingfunction 532 (AM3703) when needed to control the HVAC system, etc.Similarly, the backplate processing function 508 can be used to monitorsensors used to detect the closeness of a user, and wake the head unitprocessing system 532 and/or the electronic display when it isdetermined that a user intends to interface with the thermostat.

It will be understood by one having skill in the art that the variousthermostat embodiments depicted and described in relation to FIGS. 1-5are merely exemplary and not meant to be limiting. Many other hardwareand/or software configurations may be used to implement a thermostat andthe various functions described herein below. These embodiments shouldbe seen as an exemplary platform in which the following embodiments canbe implemented to provide an enabling disclosure. Of course, thefollowing methods, systems, and/or software program products could alsobe implemented using different types of thermostats, different hardware,and/or different software.

FIG. 6 illustrates steps for automated system matching that arepreferably carried out by the same thermostat or thermostatic controlsystem that carries out one or more of the other HVAC control methodsthat are described in the instant patent specification. It has beenfound particularly desirable to make thermostat setup and governance asuser-friendly as possible by judiciously automating the selection ofwhich among a variety of available energy-saving and comfort-promotingcontrol algorithms are appropriate for the particular HVAC configurationof the home in which the thermostat is installed. At step 602, the HVACsystem features available for control by the thermostat are determinedby virtue of at least one of (i) automated wire insertion detection,(ii) interactive user interview, (iii) automated inferences ordeductions based on automated trial runs of the HVAC system at or nearthe time of thermostat installation, and (iv) automated inferences ordeductions based on observed system behaviors or performance. Examplesof such methods are described in one or more of the commonly assignedUS20120130679A1 and US20120203379A1, as well as the present application.

In relation to cooling mode operation, if it is determined that the HVACsystem includes air conditioning (step 604), which may be by virtue of adedicated air conditioning system and/or a heat pump operating in thecooling direction, then at step 606 there is enabled a smartpreconditioning feature for cooling mode operation. One example of aparticularly advantageous smart preconditioning feature is described inthe commonly assigned U.S. Ser. No. 13/632,150 [Atty. Docket No.94021-NES0257US-852484] filed even date herewith and entitled,“Preconditioning Controls and Methods for an Environmental ControlSystem”, which is incorporated by reference herein. For someembodiments, the smart preconditioning algorithm is configured to:constantly learn how fast the home heats up or cools down by monitoringthe recent heating and cooling history of the home, optionallyincorporating external environmental information such as outsidetemperatures, sun heating effects, etc.; predict how long the HVACsystem will need to actively heat or cool in order to reach a particularscheduled setpoint; and begin preconditioning toward the particularscheduled setpoint at just the right time such that the scheduledsetpoint temperature will be reached at the scheduled setpoint time.User comfort is promoted by virtue of not reaching the scheduledsetpoint temperature too late, while energy savings is promoted byvirtue of not reaching the scheduled setpoint temperature too early.

In relation to heating mode operation, if it is determined that the HVACsystem includes radiant heating (step 608), then at step 618 there isenabled a smart radiant control feature for heating mode operation. Oneexample of a particularly advantageous smart radiant control feature isdescribed in the commonly assigned U.S. Ser. No. 13/632,152 filed evendate herewith and entitled, “Radiant Heating Controls and Methods for anEnvironmental Control System”, which is incorporated by referenceherein. For some embodiments, the smart radiant control feature isconfigured to monitor radiant heating cycles on an ongoing basis,compute an estimated thermal model of the home as heated by the radiantsystem, and predictively control the radiant system in a manner thattakes into account the thermal model of the house, the time of day, andthe previous heat cycle information. The smart radiant control featureis configured to achieve comfortable maintenance band temperatures whilealso minimizing frequent changes in HVAC on/off states and minimizingHVAC energy consumption. Among other advantages, uncomfortable andenergy-wasting target temperature overshoots are avoided.

If it is determined that the HVAC system includes a heat pump includingauxiliary resistive electrical heating (i.e., so-called auxiliary or AUXheat) (step 610), and if it is further determined (step 612) that thethermostat is network-connected (such that it can receive outsidetemperature information based on location data and an internet-basedtemperature information source) or otherwise has access to outsidetemperature information (such as by wired or wireless connection to anoutside temperature sensor), then at step 616 a smart heat pump controlfeature is enabled. If at step 610 there is not a heat pump with AUXheat (which will most commonly be because there is a conventional gasfurnace instead of a heat pump, or else because there is a heat pump ina so-called dual-fuel system that does not include AUX heat), then atstep 614 there is enabled a smart preconditioning feature for heat mode,which can be a similar or identical opposing counterpart to thepreconditioning feature for cooling mode discussed supra with respect tostep 606. Similarly, if at step 612 there is no network connectivity orother access to outside temperature information, then the smart heatpump control feature of step 616 is not enabled and instead the smartpreconditioning feature of step 614 is enabled.

In reference to step 616, one example of a particularly advantageoussmart heat pump control feature is described in the commonly assignedU.S. Ser. No. 13/632,093, filed even date herewith and entitled,“Intelligent Controller For An Environmental Control System”, which isincorporated by reference herein. Although the AUX heat function allowsfor faster heating of the home, which can be particularly useful atlower outside temperatures at which heat pump compressors alone are oflesser efficacy, the energy costs of using AUX heat can often be two tofive times as high as the energy costs of using the heat pump alone. Forsome embodiments, the smart heat pump control feature is configured tomonitor heat pump heating cycles on an ongoing basis, tracking how fastthe home is heated (for example, in units of degrees F. per hour) by theheat pump compressor alone in view of the associated outside airtemperatures. Based on computed correlations between effective heatingrates and outside air temperatures, and further including a userpreference setting in a range from “Max Comfort” to “Max Savings”(including a “Balanced” selection in between these end points), thesmart heat pump control feature judiciously activates the AUX heatingfunction in a manner that achieves an appropriate balance between usercomfort and AUX heating costs. For some embodiments, the factorsaffecting the judicious invocation of AUX heat include (i) a predictedamount of time needed for the heat pump alone to achieve the currenttemperature setpoint, (ii) whether the current temperature setpointresulted from an immediate user control input versus whether it was ascheduled temperature setpoint, and (iii) the particular selected userpreference within the “Max Comfort” to “Max Savings” range. Generallyspeaking, the AUX function determination will be more favorable toinvoking AUX heat as the compressor-alone time estimate increases, morefavorable to invoking AUX heat for immediate user control inputs versusscheduled setpoints, and more favorable to invoking AUX heat for “MaxComfort” directed preferences than for “Max Savings” directedpreferences.

For some embodiments, the smart heat pump control feature furtherprovides for automated adjustment of a so-called AUX lockouttemperature, which corresponds to an outside air temperature above whichthe AUX heat will never be turned on, based on the monitored heat pumpheating cycle information and the user preference between “Max Comfort”and “Max Savings.” Generally speaking, the AUX lockout temperatures willbe lower (leading to less AUX usage) for better-performing heat pumps,and will also be lower (leading to less AUX usage) as the userpreference tends toward “Max Savings”. For some embodiments in whichthere is network connectivity available such that overnight temperatureforecasts can be provided, the smart heat pump control feature furtherprovides for night time temperature economization in which an overnightsetpoint temperature may be raised higher than a normally scheduledovernight setpoint if, based on the overnight temperature forecast, theAUX function would be required to reach a morning setpoint temperaturefrom the normal overnight setpoint temperature when morning comes.Advantageously, in such situations, even though the overnighttemperature inside the home is made higher it would otherwise be, theuser actually saves energy and money by avoiding the use of the AUXfunction when morning comes.

According to some embodiments, the determinations made at one or more ofsteps 608 and 610 can be based on automatically observed HVAC systemperformance information rather than specific system identificationinformation. For example, it may be the case that a particular heatingfunctionality of an HVAC system is not physically a radiant system, butnevertheless tends to exhibit signs of a high thermal mass combined withsubstantial control lag, making it similar in nature to a radiantheating system. For such cases, the smart radiant control feature may beenabled to improve performance. Likewise, it may not be the case thatthe HVAC system has a heat pump with AUX functionality, but it may havea two-stage heating functionality in which the first stage (which typewas likely chosen as a first stage because it was more cost-effective)tends to be very slow or “fall behind” at lower outside temperatures,and in which the second stage (which type was likely chosen as a secondstage because it was less cost-effective) tends to be verytime-effective in heating up the home, thus making the system act verymuch like a heat pump system with AUX functionality. For such cases, thesmart heat pump control feature may be enabled to improve performance.

Automatically Configuring Operational Modes

In modern network-enabled homes, many different types of devices can beused to control various aspects of the home environment, including airtemperature, humidity, fan speed, music, television, appliances, and/orthe like. These modern control devices may include a number ofconnections, both wired and wireless, to other household systems.Depending on the complexity of these connections, modern control devicesmay appear difficult to install to the average homeowner and create aperception that professional installation is required in order to enjoythe benefits of modern control devices.

Presented herein are methods and systems to help simplify the connectionconfiguration process that may otherwise prove daunting to the averagehomeowner. Specifically, the control device may mechanically orelectrically detect the available connections to other systems within anenclosure. The control device may then intelligently analyze theseconnections and determine the configurations of the other systems. Ifthe control device is able to determine the other system configurations,then the control device can operate in accordance with thoseconfigurations without requiring additional user input. However, if thecontrol device is unable to determine these configurations (i.e.multiple system configurations are possible with the same set ofconnections) then a user interface on the control device may interviewthe user to acquire the minimal amount of information necessary topinpoint the other system configurations. Additionally, connectionerrors can be detected, and-users can be alerted before possible damagecan occur to the other systems. These embodiments may simplify theinstallation process and be configured to only require user input whenabsolutely necessary.

As various methods and systems for determining and operating inaccordance with external system configurations are presented, it will beunderstood that the ensuing discussion can apply to any control unit asdescribed above. However, throughout the remainder of this disclosure aspecific type of implementation will be used, namely a thermostat. Itwill be understood that the principles described using thermostathardware and software can be easily applied to other control units byone having skill in the art in light of this disclosure.

In the case of the thermostat, the primary external system with which itwill interface is an HVAC system. Generally, an HVAC system cancommunicate with the thermostat through a plurality of HVAC controlwires. Depending on the configuration of the HVAC system, differentwires may be available. When replacing an old thermostat with a newmodern thermostat, users are typically instructed to record theconnection made by each wire to the old thermostat, and then make thesame connection to the corresponding connector on the new thermostat.For example, a wire connected to the C terminal of the old thermostatshould be connected to the C terminal of the new thermostat.

Simply duplicating in the new thermostat the connections that were madeto the old thermostat represents only half of the installationchallenge. As will be understood by one having skill in the art, manydifferent HVAC system configurations are possible depending on theclimate, the geographic location, the time of year, the age of the home,the natural resources locally available, and/or the like. For example,some homes may operate using a conventional gas-powered heater and acompressor-based air conditioner. Other homes may use a heat pump.Because of the limitations of heat pumps in extreme weather,supplemental systems may be used, such as electrical strip heat, gasheaters, radiant flooring, boilers, and/or the like. Besides heating andair-conditioning, an HVAC system may also provide other features, suchas humidifiers, dehumidifiers, fans, emergency heating, and/or the like.

When certain wire connections between the HVAC system and the thermostatare found to exist, a reliable inference can sometimes be made as to atleast part of an HVAC system configuration. For example, if a wire isconnected between the HVAC system and the O/B connector of thethermostat, then it can be reliably inferred that the HVAC system uses aheat pump. Therefore, by analyzing each of the connections to thethermostat, some or all of the system configuration can be deduced. Thedifficulty lies in the fact that different HVAC system configurationsmay use similar wire connections to the thermostat. Thus, every HVACsystem configuration cannot be deduced based solely on the wireconnections. For example, in a conventional system the Y1 wire may beused to activate an air conditioner, whereas in a heat pump system, theY1 wire may be used to activate the heat pump in cooperation with an O/Bwire. In a heat pump system, it may not be possible to determine whetherthe system is dual-fuel or single-fuel based solely on the connections.In these cases, additional user input may be required.

In cases where the HVAC system configuration can be reliably determinedbased on the wire connections, the thermostat can operate in accordancewith that system configuration without requiring additional user input.In cases such as those above where additional information may berequired, a user interface of the thermostat may present aninterview-style set of questions to the user in order to acquire theneeded information. The user interview may include instructions to visita website to educate the user on different HVAC configurations that willhelp the user understand their HVAC system. Additionally, the userinterview may include a recommendation to contact a professionalinstaller in cases where the user is confused or the HVAC system iscomplicated.

FIGS. 7A-7B are diagrams showing a thermostat backplate having aplurality of user-friendly tool-free wiring terminals, according to someembodiments. For ease of installation, the thermostat 102 is separableinto a head unit 540 and backplate 542. Shown in FIG. 7A is a plan viewof backplate 542 which has been configured for easy installation by anon-expert installer, such as an end-user. Back plate 542 includes twobanks of HVAC wire connectors, which together provide capability fortool-free connection to up to 10 HVAC system wires. A semi-circularlyarranged left bank includes 5 connectors 710, 712, 714, 716 and 718.Likewise, a semi-circularly arranged right bank includes 5 connectors720, 722, 724, 726 and 728. Although 10 wiring connectors are shown inthe embodiments of FIG. 7A, other numbers of connectors (for example 6,8 or 12 connectors) can be similarly arranged in banks of circulararrangements. A large central opening 692 is provided through which theHVAC wires can pass when backplate 542 is wall mounted. As shown in FIG.7A, the backplate is mounted using two screw fasteners 760 and 762passing through backplate mounting holes 692 and 694 respectively andanchored into wall 780. A number of HVAC system wires, for example wires772 and 774 are shown protruding through wall hole 770 and throughbackplate central opening 692. By arranging the connectors along an arcclose to the outer periphery of the backplate 542, a relatively largenumber of wiring connectors can be accommodated, with each individualconnector still being large enough to allow for ease of makingelectrical connection with HVAC wires by a non-expert without the use oftools. In particular, each wiring connector has a spring loaded,pushable button which allows for an HVAC wire to be inserted into a wirehole. For example, connector 726 has a spring loaded button 734 and awire hole 736. When the button is released, the spring action within theconnectors a wire securely grasps the wire inserted in the wire hole.Each connector is wedge shaped as shown, with the button end being widerthan the wire-hole end. In the examples shown, the button end of theconnector is 8.5 mm in width and the wire-hole end is 5.1 mm in width.In the embodiment shown, each connector occupies 15.3 degrees of an arcon the backplate 542, however, it has been found that connector widthsof between 10-20 degrees of arc to be suitable for many applications.Another important dimension from a usability standpoint has been foundto be the distance from the button surface to the wire insertionlocation (the wire hole). If the button to wire-hole distance is tooshort, it has been found that many users have difficulty in installationbecause the finger used to press the button tends to block a good viewof the wire hole. In the embodiments shown the distance from the buttoncenter to the wire hole is 12.2 mm.

By arranging the buttons in an arc-shaped pattern close to the outerperiphery of backplate 542, and by shaping each connecter in awedge-like shape, the surface area of the buttons can be maximized sincethere is more room for each button when the connectors are shaped andarranged as shown. Additionally, it has been found that it is easier formany users to press a button that is very close to the periphery of abackplate device, especially located close to the left and right edgeswhen wall-mounting a thermostat. HVAC system wires, such as wires 772and 774 are commonly 18 gauge solid (18 AWG or 1.024 mm diameter). As aresult the wires protruding from the hole in the wall are rather stiffand may be difficult to bend and otherwise manipulate. By passing theHVAC wires through a central opening 692 and arranging the connectorsclose to the outer periphery of backplate 542 and positioning the wireholes in an arc-shaped pattern surrounding the central opening, morespace is allowed the user to bend the HVAC wires. The distance d fromthe center 704 of the central opening 692 (and of the backplate 542) tothe wire hole in each connector is 21 mm. Also, since the wire holes arearranged in a circular pattern around the central opening 692, thedistance d from the wire hole to the center of the backplate is equalfor each connector, thereby aiding the installation of many wires beingthe same length protruding from wall 780 from the same hole 770. Theradial direction between the hole 770 and the wire holes of theconductors also allows for few and less complicated bending of the HVACwires during installation, since each hole is directly facing the hole770. Thus, for many reasons, the placement, shape orientation andarrangement of the connectors on the backplate 542 has been found togreatly increase the user install ability of the thermostat. An exampleof user's finger 702 is shown pressing the button of connector 728.

FIG. 7B is a perspective view of a backplate being installed on a wall,according to some embodiments. The backplate 542 is shown attached tosurface of wall 780. The user has a left hand 704 that is pressing thebutton of connector 716 while a right hand 706 is inserting a wire 750into the wire hole 746 of wiring connector 716. Note that due to theadequate distance between the button and wire hole of the connector, theuser's finger used to press the button does not block the user's view ofthe wire hole. It has been found that the combination of pressing aspring loaded button and inserting the wire in a wire hole is mucheasier for non-expert installers than conventional screw-type wireterminals which require carefully holding a wire in place whilepositioning and turning a relatively small sized screw driver.

For one embodiment, the backplate of the thermostat can be equipped witha small mechanical detection switch (not shown) for each distinct inputport, such that the insertion of a wire (and, of course, thenon-insertion of a wire) is automatically detected and a correspondingindication signal is provided to a processing system of the thermostatupon initial docking. In this way, the thermostat can have knowledge foreach individual input port whether a wire has, or has not, been insertedinto that port. Preferably, the thermostat can be also provided withelectrical sensors (e.g., voltmeter, ammeter, and ohmmeter)corresponding to each of the input wiring connectors. The thermostat canthereby be enabled, by suitable programming, to perform some fundamental“sanity checks” at initial installation. By way of example, if there isno input wire at either the Rc or Rh terminal, or if there is no ACvoltage sensed at either of these terminals, further initializationactivity can be immediately halted, and the user notified on the userinterface, because there is either no power at all or the user hasinserted the Rc and/or Rh wires into the wrong terminal. By way offurther example, if there is a live voltage on the order of 24 VACdetected at any of the W, Y, and G terminals, then it can be concludedthat the user has placed the Rc and/or Rh wire in the wrong place.Throughout the remainder of this disclosure, these capabilities will bereferred to separately as “mechanical detection” and “electricaldetection.”

In some embodiments, it has been found particularly useful for thethermostat itself to be self-contained such that a knowledge base ofpossible HVAC system configurations is stored within the thermostat. Theuser interface may provide wiring charts, scenario diagrams,interview-style questions, and so forth that have been preloaded on thethermostat in order to facilitate easy installation. This may provide auser with all of the instructions necessary for installation withoutrequiring network activity to access a URL or website information. Inother embodiments, the thermostat may instead be provided with wireinsertion sensors using mechanical detection or electrical detection incombination with a communication chip and a user interface. In thiscase, the thermostat may provide wiring configuration information to thecloud server from which is retrieved possible HVAC systemconfigurations. Although this embodiment may not be self-contained likethe first embodiment, the cloud-based configuration database can beupdated constantly at the cloud server.

In still other embodiments the thermostat need not require a userinterface at all. Instead, the interface may be provided by a smartphone, PDA, or other mobile computing device. In this case, the user mayinterface with the thermostat using the mobile computing device. Thismay allow the cost of the thermostat to be greatly reduced as a userinterface may be eliminated. Additionally, the power usage of thethermostat may be conserved by not requiring a user interface. Ofcourse, the installation methods described herein for determining anHVAC system configuration may also operate using the mobile computinginterface.

It will be understood in light of this disclosure that one having skillin the art could readily combine any of these methods for providinginstallation information. Namely, information may be stored a priori onthe thermostat, provided by a cloud server, and or interfaced with amobile computing device, depending on the particular embodiment and usethereof. However, it has been discovered that storing all or most of theinformation required for installation on the thermostat can be mostadvantageous because no network connection is required. This avoids aso-called “chicken and egg” problem, wherein users without networkconnections cannot access installation information, and they are unableto diagnose the problem because they have no network connection. Thisscenario causes many users to simply give up and return the thermostatin exchange for a more basic model that does not provide advancedfunctionality.

FIG. 8 illustrates a flowchart 800 of a method for determining an HVACconfiguration using wire connectors, according to one embodiment. Themethod may include detecting a change in the thermostat wiring (802).The change may be detected using mechanical detection techniques and/orelectrical detection techniques as described above. In one embodiment, adelay may be added such that these changes are not detected until aftera batch of changes has been made, such as during installation processafter the thermostat is assembled. This detection may also be carriedout by a connection sensing module coupled to a plurality of HVACconnectors. The connection sensing module may be configured to determinethe identities of a first subset of the plurality of HVAC connectorsinto which corresponding HVAC wires have been inserted.

The method may also include determining identities of the wireconnectors (804). In one embodiment, this step may comprise a processingsystem that is configured to process the identities of the subset ofHVAC connectors to determine a configuration of the HVAC system to becontrolled.

The method may further include determining whether multiple HVAC systemconfigurations are indicated by the connected wires (806). In oneembodiment, this may be determined by identifying, based on theidentities of the first subset of identified HVAC connectors, whether(i) only a single possible HVAC system configuration is indicatedthereby, or (ii) multiple possible HVAC system configurations areindicated thereby.

If it is determined that only a single possible HVAC systemconfiguration is indicated, then the method may include operating theHVAC system according to the single possible HVAC system configuration(810). Alternatively, if it is determined that multiple HVACconfigurations are possible, the method may include resolving themultiple possible HVAC system configurations down to a particular oneHVAC configuration (808). In one embodiment, the multiple HVAC systemconfigurations may be resolved based on at least one user response to atleast one inquiry to a user presented on a user interface. Examples ofsuch user interfaces may be discussed further herein below. After themultiple HVAC system configurations have been resolved to a single HVACconfiguration, the system may then operate in according to theparticular HVAC system configuration (810).

It should be appreciated that the specific steps illustrated in FIG. 8provide particular methods of determining an HVAC system configurationaccording to various embodiments of the present invention. Othersequences of steps may also be performed according to alternativeembodiments. For example, alternative embodiments of the presentinvention may perform the steps outlined above in a different order.Moreover, the individual steps illustrated in FIG. 8 may includemultiple sub-steps that may be performed in various sequences asappropriate to the individual step. Furthermore, additional steps may beadded or removed depending on the particular applications. One ofordinary skill in the art would recognize many variations,modifications, and alternatives.

The method described above can be implemented using virtually anycontrol unit for an enclosure. In the case of a thermostat, the methoddescribed above can be used to configure the thermostat to be compatiblewith virtually any HVAC system configuration. The particular thermostatdescribed herein includes ten distinct HVAC wire connectors. However, itwill be understood that other thermostat embodiments may include more orfewer HVAC wire connectors, which may have different names or labelsassociated with HVAC wires. Depending on which wires are available, andwhich wire connectors are used by the particular thermostat embodiment,different logical algorithms may be used to determine an HVACconfiguration.

In order to provide an enabling disclosure, a description is providedbelow for one particular logical algorithm used in a preferredthermostat embodiment. In light of this disclosure, one having skill inthe art can readily adapt the algorithm described below to be compatiblewith virtually any HVAC system configuration. This exemplary algorithmcan be implemented using high or low level programming languages on amicrocontroller or microprocessor in the thermostat embodiments. Forexample, the flowcharts and algorithms described below may beimplemented, for example, using “switch” statements or a nested seriesof “if-then-else” control structures. It should be noted that the exactorder of operations described below is merely exemplary, and not meantto be limiting. Alternate embodiments could vary both the order in whichmechanical connections are tested and the logical pathways dependent onthe results of detecting mechanical connections.

FIG. 9 illustrates a flowchart 900 of a method of determining whether anHVAC system uses a heat pump, according to one embodiment. In thisembodiment, it can first be determined whether a wire has beenmechanically inserted into an O/B connector of the thermostat (902). TheO/B wire can be used to control the direction of a heat pump, i.e.whether the heat pump is heating or cooling the inside of the enclosure.Generally, the O/B wire is not used in a conventional HVAC system. Asused herein, the term “conventional” may be used to refer to any HVACsystem that does not use a heat pump. Therefore, if a wire is notmechanically detected in the O/B connector, it can be reliablydetermined that the HVAC system uses a conventional heater and/or airconditioner (904). The discussion for conventional systems continues inrelation to FIG. 10 described herein below.

Next, the method may determine whether a wire is mechanically detectedat the Y1 connector (906). Generally, the Y1 wire is used to activatethe heat pump. If no wire is detected at the Y1 connector, then this mayresult in an error condition (908). For example, a message can bedisplayed on the user interface informing the user that a Y1 wire is notdetected, and the heat pump requires a Y1 wire. The user could also bereferred to a website explaining the issue and providing moreinformation. Refer to FIGS. 14-18 later in this disclosure for adiscussion of addressing errors and/or ambiguities using the userinterface of the thermostat.

If a wire is detected at the Y1 connector, it may next be determinedwhether a wire is mechanically detected at the W3 connector (910). Atthis point, the thermostat knows that it is dealing with a heat pumpbased HVAC system; however, many different heat pump configurations canexist. In this particular embodiment, the W3 wire can be used tosegregate the various possible heat pump configurations into twocategories. The first category of heat pump systems uses the W3 wire(914), and will be discussed in relation to FIG. 12 below. Similarly,the second category of heat pump system does not use the W3 wire (912),and will be discussed in relation to FIG. 13 below.

FIG. 10 illustrates a flowchart 1000 of a method for determining an HVACsystem configuration for a conventional HVAC system, according to oneembodiment. Flowchart 1000 may be considered a continuation of flowchart900 from FIG. 9. At this point, it may have already been establishedthat a conventional HVAC system—rather than a heat pump—is connected tothe thermostat because no O/B wire was connected (1002). Next, it can bedetermined whether a wire is mechanically detected at the E connector.If an E wire is detected, an error may be displayed on the userinterface informing a user that the E wire should only be connected whenan O/B wire is connected in a heat pump system (1006).

Next, it can be determined whether a wire is mechanically detected atthe W3 connector (1008). If a W3 wire is not detected, then it may bepossible to determine that a one-stage or a two-stage conventionalheating unit is connected to the thermostat (1010). This option may beprocessed in accordance with the flowchart discussed below in relationto FIG. 11 below. If a W3 wire is mechanically detected, then it cannext be determined whether a wire is mechanically detected at the W2/AUXconnector (1012). If a W2/AUX wire is not detected, then an error may bedisplayed on a user interface explaining that a W3 wire also requires aW2/AUX wire (1014). Next, it can be determined whether a wire ismechanically detected at the W1 connector (1016). If a W1 wire is notdetected, then an error may be displayed on the user interface thatadditional wires may be required because the W2/AUX wire has beendetected by itself (1034).

Next, it can be determined whether a wire is mechanically detected atthe Y2 connector (1018), as well as whether a wire is mechanicallydetected at the Y1 connector (1020, 1026). If a Y2 wire is connected buta Y1 wire is not connected, then an error may be displayed on a userinterface informing a user that a Y2 wire requires a Y1 wire (1022). Ifboth a Y1 wire and a Y2 wire are connected, then the thermostat maydetermine that a three-stage conventional heating with a two-stageconventional cooling HVAC system configuration is present (1024). If aY1 wire is connected without a Y2 wire, then the thermostat maydetermine that a three-stage conventional heating and one-stageconventional cooling HVAC system configuration is present (1030).Finally, if it is determined that neither the Y1 wire nor the Y2 wire isconnected, then it may be determined that a three-stage conventionalheating HVAC system configuration is present (1028).

One-stage or two-stage conventional heating systems can be detected bycontinuing on from flowchart 1000 at step 1010. FIG. 11 illustrates aflowchart 1100 of a method for determining an HVAC system configurationfor one-stage or two-stage conventional heating, according to oneembodiment. As previously detected, based on the absence of a wire inthe W3 connector, it may be determined a one-stage or two-stageconventional heating HVAC system configuration may be present (1102).

Next, it may be determined whether a wire is mechanically detected atthe W2/AUX connector of the thermostat (1104), as well as whether a wireis mechanically detected at the W1 connector of the thermostat (1106,1112). If a W2/AUX wire is detected without a W1 wire, then an error maybe displayed on the user interface that additional wires may be requiredbecause the W2/AUX wire has been detected by itself (1108). If a W2/AUXwire and a W1 wire are both detected, then a two-stage conventionalheating system may be determined to be present (1110). Depending on thepresence of the Y1 and Y2 wires, either a one-stage or a two-stagecooling system may also be present. If no W2/AUX wire is connected, buta W1 wire is connected, then an error may be present. Again, dependingon the presence of the Y1 and Y2 wires, either a one-stage or atwo-stage cooling system may also be present. Finally, if neither aW2/AUX wire or a W1 wire are connected, then depending upon the presenceof the Y1 and Y2 wires, either a one-stage or a two-stage cooling systemmay be present without a heating system.

Turning back briefly to FIG. 9, if an O/B wire was mechanicallydetected, then a heat pump system was determined to be connected to thethermostat. Assuming that a connection was also made to the Y1connector, it could be assumed that either a single-fuel system or adual-fuel system configuration was present. FIG. 12 illustrates aflowchart 1200 of a method for determining an HVAC system configurationfor a heat pump system with the W3 wire connection (continuing from step914 of FIG. 9), according to one embodiment. After detecting the W3wire, it may next be determined whether connections are made to theW2/AUX connector and/or the W1 connector (1204, 1214, 1224, 1234).

The next step in the method can be modified to include inputs other thanmechanical wire connections. In this particular embodiment, a userinterface may be configured to present a user with an interview-stylequestion(s) to determine whether the heat pump is single-fuel ordual-fuel. Depending upon one or more inputs provided to the userinterface in response to the interview style question(s), the thermostatmay then determine whether a final HVAC system configuration can bedetermined, or whether an error message should be presented on the userinterface.

Similarly, FIG. 13 illustrates a flowchart 1300 of a method fordetermining an HVAC system configuration for a heat pump system withoutthe W3 wire connection (continuing from step 912 of FIG. 9), accordingto one embodiment. Again, a user interface may be configured to presenta user with an interview-style question(s) to determine whether the heatpump is single-fuel or dual-fuel. Depending upon one or more inputsprovided to the user interface in response to the interview stylequestion(s), the thermostat may then determine whether a final HVACsystem configuration can be determined, or whether an error messageshould be presented on the user interface.

It will be understood that numerous details and decisions may have beenomitted from the flowcharts illustrated in FIGS. 9-13 for brevity. Forexample, instead of illustrating final HVAC system configurations inflowchart 1200, an indication of whether a final system configurationcould be determined was presented. One having skill in the art could usethe flowcharts and discussion included herein to readily fill in theremaining details. For convenience and to provide an enablingdisclosure, listed below is an exemplary pseudocode implementation ofthese flowcharts that may be implemented by any digital or analogcomputing or processing system. Of course, many other specificimplementations would be readily understood in light of this disclosure,and this example could be edited or altered depending on the particularembodiment, location, and/or HVAC system.

HVAC Control Wire Check [O/B, W1, W2/AUX, W3, Y1, Y2, E]

a. O/B detected mechanically

-   i. Y1 not detected mechanically [Error]-   ii. Y1 detected mechanically    -   1. W3 detected mechanically        -   a. W1 and W2/AUX detected mechanically            -   i. Dual fuel selected [Error]                -   1. O/B, Y1, W3, W1, W2/AUX [one-stage heat pump                    heating and cooling with three-stage conventional                    heating]                -   2. O/B, Y1, W3, W1, W2/AUX, Y2 [two-stage heat pump                    heating and cooling with three-stage conventional                    heating]            -   ii. Dual fuel not selected [Error]                -   1. O/B, Y1, W3, W1, W2/AUX [one-stage heat pump                    heating and cooling with three-stage electric strip                    heating]                -   2. O/B, Y1, W3, W1, W2/AUX, Y2 [two-stage heat pump                    heating and cooling with three-stage electric strip                    heating]        -   b. W1 detected mechanically but W2/AUX not detected            mechanically            -   i. Dual fuel selected [OK]                -   1. O/B, Y1, W3, W1 [one-stage heat pump heating and                    cooling with two-stage conventional heating]                -   2. O/B, Y1, W3, W1, Y2 [two-stage heat pump heating                    and cooling with two-stage conventional heating]            -   ii. Dual fuel not selected [Error]                -   1. O/B, Y1, W3, W1 [one-stage heat pump heating and                    cooling with two-stage electric strip heating]                -   2. O/B, Y1, W3, W1, Y2 [two-stage heat pump heating                    and cooling with two-stage electric strip heating]        -   c. W2/AUX detected mechanically but W1 not detected            mechanically            -   i. Dual fuel selected [OK]                -   1. O/B, Y1, W3, W2/AUX [one-stage heat pump heating                    and cooling with two-stage conventional heating]                -   2. O/B, Y1, W3, W2/AUX, Y2 [two-stage heat pump                    heating and cooling with two-stage conventional                    heating]            -   ii. Dual fuel not selected [Error]                -   1. O/B, Y1, W3, W2/AUX [one-stage heat pump heating                    and cooling with two-stage electric strip heating]                -   2. O/B, Y1, W3, W2/AUX, Y2 [two-stage heat pump                    heating and cooling with two-stage electric strip                    heating]        -   d. Neither W1 nor W2/AUX detected mechanically            -   i. Dual fuel selected [OK]                -   1. O/B, Y1, W3 [one-stage heat pump heating and                    cooling with one-stage conventional heating]                -   2. O/B, Y1, W3, Y2 [two-stage heat pump heating and                    cooling with one-stage conventional heating]            -   ii. Dual fuel not selected [OK]                -   1. O/B, Y1, W3 [one-stage heat pump heating and                    cooling with one-stage electric strip heating]                -   2. O/B, Y1, W3, Y2 [two-stage heat pump heating and                    cooling with one-stage electric strip heating]    -   2. W3 not detected mechanically        -   a. W1 and W2/AUX detected mechanically            -   i. Dual fuel selected [OK]                -   1. O/B, Y1, W1, W2/AUX [one-stage heat pump heating                    and cooling with two-stage conventional heating]                -   2. O/B, Y1, W1, W2/AUX, Y2 [two-stage heat pump                    heating and cooling with two-stage conventional                    heating]                -   3. O/B, Y1, W1, W2/AUX, E [one-stage heat pump                    heating and cooling with two-stage conventional                    heating and emergency heating]                -   4. O/B, Y1, W1, W2/AUX, Y2, E [two-stage heat pump                    heating and cooling with two-stage conventional                    heating and emergency heating]            -   ii. Dual fuel not selected [Error]                -   1. O/B, Y1, W1, W2/AUX [one-stage heat pump heating                    and cooling with two-stage electric strip heating]                -   2. O/B, Y1, W1, W2/AUX, Y2 [two-stage heat pump                    heating and cooling with two-stage electric strip                    heating]                -   3. O/B, Y1, W1, W2/AUX, E [one-stage heat pump                    heating and cooling with two-stage electric strip                    heating and emergency heating]                -   4. O/B, Y1, W1, W2/AUX, Y2, E [two-stage heat pump                    heating and cooling with two-stage electric strip                    heating and emergency heating]        -   b. W1 detected mechanically but W2/AUX not detected            mechanically            -   i. Dual fuel selected [OK]                -   1. O/B, Y1, W1 [one-stage heat pump heating and                    cooling with one-stage electric strip heating]                -   2. O/B, Y1, W1, Y2 [two-stage heat pump heating and                    cooling with one-stage electric strip heating]                -   3. O/B, Y1, W1, E [one-stage heat pump heating and                    cooling with one-stage electric strip heating and                    emergency heating]                -   4. O/B, Y1, W1, Y2, E [two-stage heat pump heating                    and cooling with one-stage electric strip heating                    emergency heating]            -   ii. Dual fuel not selected [OK]                -   1. O/B, Y1, W1 [one-stage heat pump heating and                    cooling with 1. one-stage conventional heating]                -   2. O/B, Y1, W1, Y2 [two-stage heat pump heating and                    cooling with one-stage conventional heating]                -   3. O/B, Y1, W1, E [one-stage heat pump heating and                    cooling with one-stage conventional heating and                    emergency heating]                -   4. O/B, Y1, W1, Y2, E [two-stage heat pump heating                    and cooling with one-stage conventional heating                    emergency heating]        -   c. W2/AUX detected mechanically but W1 not detected            mechanically            -   i. Dual fuel selected [OK]                -   1. O/B, Y1, W2/AUX [one-stage heat pump heating and                    cooling with one-stage electric strip heating]                -   2. O/B, Y1, W2/AUX, Y2 [two-stage heat pump heating                    and cooling with one-stage electric strip heating]                -   3. O/B, Y1, W2/AUX, E [one-stage heat pump heating                    and cooling with one-stage electric strip heating                    and emergency heating]                -   4. O/B, Y1, W2/AUX, Y2, E [two-stage heat pump                    heating and cooling with one-stage electric strip                    heating emergency heating]            -   ii. Dual fuel not selected [OK]                -   1. O/B, Y1, W2/AUX [one-stage heat pump heating and                    cooling with one-stage conventional heating]                -   2. O/B, Y1, W2/AUX, Y2 [two-stage heat pump heating                    and cooling with one-stage conventional heating]                -   3. O/B, Y1, W2/AUX, E [one-stage heat pump heating                    and cooling with one-stage conventional heating and                    emergency heating]                -   4. O/B, Y1, W2/AUX, Y2, E [two-stage heat pump                    heating and cooling with one-stage conventional                    heating emergency heating]        -   d. Neither W1 nor W2/AUX detected mechanically            -   i. Dual fuel selected [Error]                -   1. O/B, Y1 [one-stage heat pump heating and cooling                    (but no conventional 1. heating)]                -   2. 2. O/B, Y1, Y2 [two-stage heat pump heating and                    cooling (but no conventional heating)]                -   3. O/B, Y1, E [one-stage heat pump heating and                    cooling with emergency heating (but no conventional                    heating)]                -   4. O/B, Y1, Y2, E [two-stage heat pump heating and                    cooling with emergency heating (but no conventional                    heating)]            -   ii. Dual fuel not selected [OK]                -   1. O/B, Y1 [one-stage heat pump heating and cooling]                -   2. O/B, Y1, Y2 [two-stage heat pump heating and                    cooling]                -   3. O/B, Y1, E [one-stage heat pump heating and                    cooling with emergency heating]                -   4. O/B, Y1, Y2, E [two-stage heat pump heating and                    cooling and emergency heating]

b. O/B not detected mechanically

-   i. E detected mechanically [Error]-   ii. E not detected mechanically    -   1. W3 detected mechanically        -   a. W2/AUX not detected mechanically [Error]        -   b. W2/AUX detected mechanically            -   i. W1 not detected mechanically [Error]            -   ii. W1 detected mechanically                -   1. Y2 detected mechanically  a. Y1 not detected                    mechanically [Error] b. Y1 detected mechanically                    [OK]  i. W3, W2/AUX, W1, Y2, Y1 [three-stage                    conventional heating and two-stage cooling]                -   2. Y2 not detected mechanically [OK] a. W3, W2/AUX,                    W1 [three-stage conventional heating] b. W3, W2/AUX,                    Wl, Y1 [three-stage conventional heating and                    one-stage cooling]    -   2. W3 not detected mechanically        -   a. W2/AUX detected mechanically            -   i. W1 not detected mechanically [Error]            -   ii. W1 detected mechanically                -   1. Y2 detected mechanically  a. Y1 not detected a.                    mechanically [Error] b. Y1 detected mechanically                    [OK]  i. W2/AUX, Wl, Y2, Y1 [two-stage conventional                    heating and two-stage cooling]                -   2. Y2 not detected mechanically [OK] a. W2/AUX, W1                    [two-stage conventional heating] b. W2/AUX, W1, Y1                    [two-stage conventional heating and one-stage                    cooling]        -   b. W2/AUX not detected mechanically            -   i. W1 detected mechanically                -   1. Y2 detected mechanically  a. Y1 not detected                    mechanically [Error] b. Y1 detected mechanically                    [OK]  i. W1 , Y2, Y1 [one-stage conventional heating                    and two-stage cooling]                -   2. Y2 not detected mechanically [OK] a. W1                    [one-stage heating]  b. W1, Y1 [one-stage heating                    and one-stage cooling]            -   ii. W1 not detected mechanically                -   1. Y1 not detected mechanically [Error]                -   2. Y1 detected mechanically [OK] a. Y1 [one-stage                    cooling] b. Y1, Y2 [two-stage cooling]                    User Interface

During the process of determining whether an HVAC system configurationcan be determined, the thermostat may ascertain that the wiresmechanically connected to the wiring connectors form an invalidcombination that is not supported by the thermostat. In these cases, auser interface of the thermostat may be used to provide an output. Theoutput may indicate that there is an error with the wiringconfiguration. The output may also indicate possible solutions for theerror, the severity of the error, external references that may beconsulted to solve the error, and/or possible effects of the error.

FIG. 14A illustrates a user interface of a thermostat for providing anoutput describing a wiring error, according to one embodiment. Here, auser may have previously made wire connections to the wire connectors ofthe thermostat before turning the thermostat on. The thermostat may runthrough a hardware or software implementation of the logic andflowcharts described elsewhere herein to determine whether an HVACsystem configuration can be determined. In this example, a wire may bemechanically detected at the Rc connector. The thermostat may determinethat at least a Y1 or a W1 wire is necessary to run a valid HVAC system.In response, a wiring report 1402 may be presented on the userinterface. The wiring report 1402 may include an error code 1404 as wellas a message 1406 providing additional information about the errorcondition. For example, the message 1406 may explain that no heating orcooling wires were detected, and that at least a Y1 or a W1 wire isrequired. Additionally, the wiring report 1402 may include a reference1408 to an external data source where more information regarding theerror condition may be found, such as a website.

Often, users may be installing their new thermostat by themselveswithout the aid or advice of a professional HVAC installer. Therefore,additional information may be provided on the user interface in order tosimplify the installation process. For example, pictures of the wiringcondition may be provided to the user along with graphicalrepresentations and/or animations that illustrate how the error may bediagnosed and/or solved. FIG. 14B illustrates a user interface of athermostat providing a graphical output of mechanical wiring connectionsthat have been detected, according to one embodiment. Here, each of aplurality of HVAC wire connectors 1410 may be illustrated for user. Forexample, the plurality of HVAC wire connectors 1410 may be arrangedgraphically on the user interface to match the actual physicalarrangement provided by the thermostat. Notice that the plurality ofHVAC connectors 1410 displayed by the user interface are arrangedsimilarly to the physical arrangement shown in FIG. 7A. In this case,the connectors are arranged radially along the perimeter of thethermostat. In other embodiments, they may be arranged in a gridpattern, and oval pattern, or any other arrangement.

The user interface can show an electrical connection made for each ofthe plurality of HVAC wire connectors 1410. For example, electricalconnection 1412 made to the Rc wire connector shows that a power wirehas been electrically sensed at the connector. Furthermore, the wireconnectors that are implicated by the error may also be highlighted. Forexample, the Y1 and the W1 connectors may have a different color,outline, or other such indicator arranged to draw a user's attention tothose connectors. In this embodiment, a color or shading of theconnectors implicated by the error has been altered compared to theconnectors not responsible for or related to the error in the graphicdisplay.

These types of informative and instructive user interfaces may becomeeven more important as the wiring configurations become more complex.FIG. 15A illustrates a user interface of a thermostat providing agraphical output of multiple wiring connections, according to oneembodiment. As before, a wiring report 1502, an error code 1504, amessage 1506, and a reference 1508 may be provided by the userinterface. In this case, the message 1506 may inform a user thatadditional wires are connected in addition to the AUX/W2 wire. This maycorrespond to a case similar to that of step 1034 of FIG. 10, where aconventional HVAC system is detected with an AUX/W2 connection without aW1 connection.

FIG. 15B illustrates a corresponding user interface of a thermostatproviding a graphical wiring diagram, according to one embodiment. Here,the plurality of HVAC wire connectors 1510 may show connections 1512that have been mechanically detected. Here, valid connections have beenmade to the Y1 connector, the Rc connector, and the W2/AUX connector.Additionally, the graphical representation of the W1 connector may behighlighted such that the user may match the graphical representation tothe actual HVAC connector layout and remedy the error by making theproper connection.

In addition to providing information related to installation and wiringerrors, the user interface may also be configured to provide validconfiguration information to the user. FIG. 16A illustrates a userinterface of a thermostat providing a graphical description of a currentwiring configuration, according to one embodiment. In this embodiment,each wire at which a mechanical connection is detected may be selectedusing the user interface in order to bring up additional informationrelated to that connection. For instance, the user interface may allow auser to cycle through each connection and verify that it is beinginterpreted correctly by the thermostat. Each connection may becolor-coded or otherwise highlighted to show users connections that havebeen checked and connections that still need to be checked.

In this example, a message 1602 may be displayed for each connectiondescribing how the thermostat is interpreting the connection. Forinstance, the Y1 connection may be interpreted by the thermostat tocontrol an electric air conditioner using forced air. If a userdetermines that this is an incorrect interpretation of the wiringconnection, the user may select the Y1 connection using the userinterface and navigate to a screen providing interactive options forchanging the way the Y1 connection is interpreted.

FIG. 16B illustrates a thermostat user interface providing additionalinformation for a particular connector, according to one embodiment. Ifa user selects the Y1 connection in the previous interface, theinterface of FIG. 16B may show that the thermostat will operateaccording to the displayed characteristics of the Y1 wire. Assuming thatno O/B wire is connected, the Y1 wire may be construed to operate aconventional cooling system. The source may be electrical, and thecooling system may operate with a forced air delivery. In some caseswhere multiple options are available, a user may select either thesource, type, or delivery associated with the Y1 wire and choose adifferent option from a menu that may be displayed on the userinterface.

The user interface may also be adaptable such that it can handle manydifferent types of HVAC system configurations. Some HVAC systems mayinclude additional wires that are not specifically labeled on the HVACconnectors of the thermostat. Additional features such as radiant floorheating, humidifiers, dehumidifiers, emergency heating systems, secondstages for heating and cooling systems, and/or the like may be numerous,and thus it would be impractical to provide a dedicated wire connectorfor each option that may be rarely used. In order to handle thesevarious additional options, certain embodiments described herein willinclude a wildcard connector labeled with, for example, an asterisk or astar. The thermostat function associated with this connector may beconfigured by a user using the user interface to handle one of the manyvarious optional HVAC features that may be available.

FIG. 17A illustrates a thermostat with a user interface displaying aconnection to the wildcard connector, according to one embodiment. Inthis embodiment, the user interface may display a currently selectedfunction 1702 when the wildcard connector is selected. In this case, thewildcard connector is configured to operate a bypass humidifier (i.e. ahumidifier that requires concurrent heat). In this particularembodiment, the functions associated with the wildcard connector aredisplayed as part of a check routine for each connector. Generally, if awire is connected to the wildcard connector, the thermostat may providea graphical display similar to that of FIG. 17A such that the user canconfigure the function of the wildcard connector before the thermostatbegins operating. This may take place during an installation routine.

FIG. 17B illustrates a thermostat with a user interface displaying aconfiguration screen for the wildcard connector, according to oneembodiment. In this case, the user interface may be used to change thefunction of the wildcard connector to a dehumidifier used with the airconditioner (i.e. an air conditioner with a dehumidifying mode). Thedehumidifier may be activated by energizing the wildcard connector. Bothof these settings, along with other settings that may not be shownexplicitly, may be changed using this or a similar user interface.

The user interfaces provided thus far may allow users to make bothsimple and complex changes to the way their thermostat interacts withtheir HVAC system. These user interfaces may provide a simplifiedprocess that enables the average homeowner to perform even difficultinstallation procedures. However, in some cases the installation processmay become too difficult for the average homeowner. Modern HVAC systemsmay become very complex, and incorrect wiring may cause unexpected HVACactivity, uncomfortable environmental conditions, or even equipmentdamage.

In order to prevent these unpleasant outcomes, some embodiments mayintelligently determine when an installation process or HVACconfiguration may require a professional installer. This determinationmay be made while the thermostat is analyzing the mechanically-sensedwire connections. This determination may also be made while thethermostat is receiving configuration inputs from a user via the userinterface. The thermostat may be configured to detect common errors,configurations that are known to cause damage, unknown configurations,or even user confusion. For example, a user making numerous changesthroughout the installation process may be determined to be ill-equippedto confidently install his or her own thermostat without causing damage.

When a professional installation is considered to be desirable for aparticular installation, the thermostat may provide a message on theuser interface recommending a professional installer. Some embodimentsmay provide a reference to a website or to another resource for findingprofessional installers well-versed with the particular type of HVACsystem and/or thermostat. A user may then heed the warning provided bythe thermostat and contact the professional installer, or the user mayoverride the warning and continue with the installation process.

Additionally, a user may be able to select professional setup. FIG. 18Aillustrates a settings screen for accessing a professional setupinterface. A professional setup interface may provide additional optionsthat are not provided to a regular homeowner. These options may besegregated into the professional setup interface in order to simplifythe installation process for a regular homeowner. Additionally, theseoptions may be complex and may require special training and/orexperience. In one embodiment, a warning may be presented to a user whenselecting the professional setup interface. FIG. 18B illustrates awarning that may be displayed for professional setup, according to oneembodiment. For example, a warning may provide a description of thedangers of proceeding with the professional setup interface withoutproper training The interface may also provide an option 1802 allowingthe user to continue with the professional setup interface or to go backto the regular setup interface.

Whereas many alterations and modifications of the present invention willno doubt become apparent to a person of ordinary skill in the art afterhaving read the foregoing description, it is to be understood that theparticular embodiments shown and described by way of illustration are inno way intended to be considered limiting. Therefore, reference to thedetails of the preferred embodiments is not intended to limit theirscope.

What is claimed is:
 1. A thermostat, comprising: a processing system configured to control a heating, ventilation, and air conditioning (HVAC) system; a plurality of first HVAC connectors configured to receive a corresponding plurality of first HVAC control wires from the HVAC system, each of the plurality of first HVAC connectors being associated with a single possible HVAC function; one or more second HVAC connectors configured to receive a corresponding one or more second HVAC control wires from the HVAC system, each of the one or more second HVAC connectors being associated with a plurality of possible HVAC functions; and a connection sensing module coupled to the plurality of first HVAC connectors and coupled to the one or more second HVAC connectors and configured to determine which of the plurality of first HVAC connectors and which of the one or more second HVAC connectors have wires inserted therein; wherein the processing system is further configured to: cause to be displayed, on a user interface, graphical icons representative of each of the plurality of first HVAC connectors and each of the one or more second HVAC connectors, wherein graphical icons corresponding to HVAC connectors with wires inserted therein are visually distinguished from graphical icons corresponding to HVAC connectors without wires inserted therein; cause to be displayed, for any of the one or more second HVAC connectors having wires inserted therein, a display of at least some of the plurality of possible HVAC functions that can be associated with each of the one or more second HVAC connectors; receive input, for any of the one or more second HVAC connectors having wires inserted therein, selecting ones of the plurality of possible HVAC functions to assign to each of the one or more second HVAC connectors; determining an HVAC system configuration based on which of the plurality of first HVAC connectors have wires inserted therein, and based on any input selecting ones of the plurality of possible HVAC functions to assign to each of the one or more second HVAC connectors; and operate, if possible, the thermostat at least in part according to the determined HVAC system configuration.
 2. The thermostat of claim 1 wherein the processing system is further configured to receive input verifying that the displayed graphical icons representative of each of the plurality of first HVAC connectors and each of the one or more second HVAC connectors are correct.
 3. The thermostat of claim 1 wherein the graphical icons are visually arranged on the user interface according to an actual physical position of the corresponding first HVAC connectors on the thermostat.
 4. The thermostat of claim 1 wherein the graphical icons representative of each of the plurality of first HVAC connectors comprise a display of the single possible HVAC functions assigned to each of the plurality of first HVAC connectors.
 5. The thermostat of claim 1 wherein at least one of the one or more second HVAC connectors comprises a wildcard connector that can be configured to interface with a plurality of different HVAC system components.
 6. The thermostat of claim 1 wherein said connection sensing module is configured to determine which of the plurality of first HVAC connectors and which the one or more second HVAC connectors have wires inserted therein using mechanical sensing.
 7. The thermostat of claim 1 wherein said connection sensing module is configured to determine which of the plurality of first HVAC connectors and which the one or more second HVAC connectors have wires inserted therein using electrical sensing.
 8. The thermostat of claim 1 wherein the processing system is further configured to: determine that the determined HVAC system configuration is not a recognized HVAC system configuration by the thermostat; and cause a warning to be displayed on the user interface indicating that the HVAC system configuration is not a recognized HVAC system configuration by the thermostat.
 9. The thermostat of claim 1 wherein the plurality of possible HVAC functions comprises operating a humidifier or operating a dehumidifier.
 10. The thermostat of claim 1 further comprising a mounting plate to which the plurality of first HVAC connectors and the one or more second HVAC connectors are mounted, the mounting plate having a hole in the center portion thereof through which the plurality of first HVAC control wires and the one or more second HVAC control wires can be routed to the plurality of first HVAC connectors and the one or more second HVAC connectors, respectively.
 11. A method of determining a heating, ventilation, and air conditioning (HVAC) system configuration by a thermostat, the method comprising: determining which of a plurality of first HVAC connectors and which of one or more second HVAC connectors have wires inserted therein, wherein: the plurality of first HVAC connectors are configured to receive a corresponding plurality of first HVAC control wires from the HVAC system, each of the plurality of first HVAC connectors being associated with a single possible HVAC function; and the one or more second HVAC connectors are configured to receive a corresponding one or more second HVAC control wires from the HVAC system, each of the one or more second HVAC connectors being associated with a plurality of possible HVAC functions; causing to be displayed, on a user interface, graphical icons representative of each of the plurality of first HVAC connectors and each of the one or more second HVAC connectors, wherein graphical icons corresponding to HVAC connectors with wires inserted therein are visually distinguished from graphical icons corresponding to HVAC connectors without wires inserted therein; causing to be displayed, for any of the one or more second HVAC connectors having wires inserted therein, a display of at least some of the plurality of possible HVAC functions that can be associated with each of the one or more second HVAC connectors; receiving input, for any of the one or more second HVAC connectors having wires inserted therein, selecting ones of the plurality of possible HVAC functions to assign to each of the one or more second HVAC connectors; determining an HVAC system configuration based on which of the plurality of first HVAC connectors have wires inserted therein, and based on any input selecting ones of the plurality of possible HVAC functions to assign to each of the one or more second HVAC connectors; and operating, if possible, the thermostat at least in part according to the determined HVAC system configuration.
 12. The method of claim 11 further comprising receiving input verifying that the displayed graphical icons representative of each of the plurality of first HVAC connectors and each of the one or more second HVAC connectors are correct.
 13. The method of claim 11 wherein the graphical icons are visually arranged on the user interface according to an actual physical position of the corresponding first HVAC connectors on the thermostat.
 14. The method of claim 11 wherein the graphical icons representative of each of the plurality of first HVAC connectors comprise a display of the single possible HVAC functions assigned to each of the plurality of first HVAC connectors.
 15. The method of claim 11 wherein at least one of the one or more second HVAC connectors comprises a wildcard connector that can be configured to interface with a plurality of different HVAC system components.
 16. The method of claim 11 wherein determining which of a plurality of first HVAC connectors and which of one or more second HVAC connectors have wires inserted therein comprises using mechanical sensing.
 17. The method of claim 11 wherein determining which of a plurality of first HVAC connectors and which of one or more second HVAC connectors have wires inserted therein comprises using electrical sensing.
 18. The method of claim 11 further comprising: determining that the determined HVAC system configuration is not a recognized HVAC system configuration by the thermostat; and causing a warning to be displayed on the user interface indicating that the HVAC system configuration is not a recognized HVAC system configuration by the thermostat.
 19. The method of claim 11 wherein the plurality of possible HVAC functions comprises operating a humidifier or operating a dehumidifier.
 20. A thermostat comprising: a processing system; a plurality of HVAC connectors configured to receive a corresponding plurality of HVAC control wires; a connection sensing circuit coupled to the plurality of HVAC connectors and configured to provide an indication to the processing system of whether a wire is inserted for each of the plurality of HVAC connectors; and wherein the processing system is configured to: receive an indication from the connection sensing circuit when an HVAC connector in the plurality of HVAC connectors has a wire inserted therein, the HVAC connector being associated with a plurality of possible HVAC functions; cause to be displayed, the plurality of possible HVAC functions on a user interface; receive input selecting one of the possible HVAC functions for the HVAC connector; and operate the selected HVAC function through the HVAC connector. 